Infeed chute with wings for dual cranes

ABSTRACT

An infeed chute for a debarking drum is provided which is adapted to accommodate infeed from two log cranes simultaneously or nearly simultaneously. The chute has a central feed plate of relatively small width and trough plates of relatively great width and at a gentle slope, thereby to provide a smoothly and slightly inclined trough. Furthermore, wing plates are provided which not only define containing side walls but continue and extend the trough width to receive a plurality of log loads and yet smoothly guide the same towards a common inlet. Desirably, to accommodate the gentle slope and increased width of the chute assembly, three transition plates are provided adjacent the debarker inlet to round out the flow thereinto.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an infeed chute for a debarking drum and, inparticular, to an infeed chute designed to accommodate two log cranesfor simultaneous or near simultaneous feed from both cranes.

2. Description of the Related Art

A variety of systems have heretofore been provided for delivering logsto the inlet end of a debarking drum. One conventional method ofdelivery is to provide an infeed chute for receiving logs from a logcrane and guiding those logs end first into the debarking drum.

A concern with all infeed chute systems is that the chute guide the logsinto the debarking drum in a manner so that the logs do not bind or clogat the drum inlet so that there is a smooth, relatively continuousinfeed into the debarking drum and so that there is effective debarkingof the logs with a minimal risk that the logs being infed will bewhipped around and pieces thereof ejected from the infeed chute, whichwould endanger workers in the area.

A typical log crane 10 and infeed chute 12 are shown by way of examplein FIG. 1. As shown, the logs which in the illustrated configuration aretree-length are stored in a storage pile 14, which may be circular, asshown. The storage pile 14 is interrupted to accommodate the infeedchute 12 and debarking drum 16 substantially along the path defined bythe storage pile and also to allow log trucks 18 to bring logs to thevicinity of the storage pile 14 so that the log crane 10 can remove logsfrom such trucks 18 and store the same in the storage pile 14.

The log crane 10 is provided to retrieve logs from the storage pile 12,carry the load of logs to the infeed chute 14 and release that load oflogs downwardly and into the debarking drum 16. Thus, infeed into thedrum is limited to a sequence of loads, the size of which is determinedby the capacity of the log crane 10. Furthermore, feed of logs isinterrupted as the log crane 10 is used to locate, retrieve and conveylogs from the storage pile 12 to the infeed chute 14. Thus, such priorart log crane/infeed chute systems were limited by the capacity of thelog crane and the time required to retrieve logs from storage pile andconvey the same to the infeed chute.

In order to ensure that the logs are smoothly guided into the debarkingdrum 16, the infeed chute 12 has a width only slightly greater than theinlet to the debarking drum 16 (FIG. 1) and, like a funnel, guides thelogs into the debarking drum 16. More particularly, a top plan view ofthe conventional chute of FIG. 1 is shown in FIG. 2. As can be seen, acentral plate 20 of about two-thirds the diameter of the debarking drumpasses centrally down the length of the infeed chute 12. Twosubstantially triangular plates 22 are disposed on either side of thecentral plate 20 to define trough walls at the inlet end of the chute 12as shown in FIG. 3. The trough walls 22 have a width equal to about onehalf the diameter of the drum 16 at the inlet end of the chute (FIG. 3).The trough walls are defined at an angle A of greater than about 155 andless than about 165 degrees with respect to the central plate 20.

Another pair of triangular plates 24 are defined along a substantialportion of the trough to define severely sloping side walls to moresteeply guide the logs into the debarking drum 16, as shown in FIG. 4.In this view, it can be seen that angle A remains between 155 and 165degrees whereas angle B, defined between each plate 24 and respectiveplate 22, is greater than about 115 and less than about 125 degrees.

As shown in FIG. 5, as the debarking drum is approached, the troughwalls or plates 22 have become quite narrow and the severely slopingside walls 24 define a substantial portion of the trough therebyconcentrating the logs in the center of the chute to deliver the sameinto the debarking drum 16. Here again, angle A is greater than about155 and less than about 165 degrees and angle B is greater than about115 and less than about 125 degrees.

Adjacent the debarking drum inlet, as can best be seen in FIGS. 6 and 2,two plate segments 26,28 are mounted on each side of and to the centralplate 20, trough wall plates 22 and vertical side wall plates 24, todefine a transition to the debarking drum inlet. Specifically, atriangular plate 26 is mounted to the cut away distal end of centralplate 20 and four sided plate 28 is mounted or coupled to the triangularplate 26, trough plate 22 and side wall 24. As shown in FIG. 6, plates26 and 28 round out the trough immediately adjacent the inlet of thedebarking drum to guide the logs thereinto.

Thus, the illustrated single crane infeed chute 12 is relatively narrowand provides a generally uniformly deepening trough with containing sidewalls 24 and very gradually narrowing trough walls 22 to guide the logsinto the debarking drum. The capacity of that infeed chute, however, islimited to the intermittent single crane load, as described above.Debarking drums, on the other hand, are not necessarily so limited tosuch an intermittent, relatively small load. Indeed conventionaldebarking drums can receive a greater load and more continuously. Inaddition, debarking drums can be fairly readily scaled up to have agreater diameter and/or greater length to accommodate a greater logflow.

In order to maximize the amount of wood which can be processed in a chipmill during a given period of up or operational time, it would bedesirable to increase the rate at which logs are infed into a debarkingdrum of either conventional or increased capacity. The efficiency of theinfeed chute system described above may be increased by providing twolog cranes operating in tandem to thereby reduce the delay experiencedwhen a single crane retrieves another load of logs to be infed. However,such a second crane must wait until the first load of logs has beenfully or substantially received into the debarking drum to ensure thatthe logs will not bind at the drum inlet because the above describedconventional infeed chute is designed to accommodate only a single loadof logs.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a more efficientchipping assembly wherein the infeed of logs to the debarking drum ismaximized by providing an infeed chute which allows dual cranes tosimultaneously or nearly simultaneously deliver logs whereby fulladvantage can be taken of the capacity of a single debarking drum andthe delay which necessarily results from retrieval of loads by thecranes can be minimized by concurrent crane operation. Thus, the infeedchute of the invention which is designed to accommodate two log cranesby receiving loads from two log cranes simultaneously or nearlysimultaneously, allows delivery of a second load to the infeed chutewith out a binding of the logs at the debarking drum inlet.

To achieve the foregoing object, an infeed chute for a debarking drum asprovided which has a width at the uppermost, inlet edge thereofsubstantially greater than conventional infeed chutes but which has aseries of funneling plates which smoothly guide logs deposited thereontowards the single debarking drum inlet in a manner which minimizesejection of logs or portions of logs and binding of logs at the inlet tothe conveyor.

Other objects, features and characteristics of the present invention, aswell as the methods of operation and functions of the related elementsof the structure, and the combination of parts and economies ofmanufacture, will become more apparent upon consideration of thefollowing detailed description and the appended claims with reference tothe accompanying drawings, all of which form a part of thisspecification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial, schematic, perspective view of a conventionalsingle log crane chip mill;

FIG. 2 is a top plan view of a conventional single log crane infeedchute;

FIG. 3 is a cross-sectional view, with the support frame broken away forclarity, taken along line 3--3 of FIG. 2;

FIG. 4 is a cross-sectional view, with the support frame broken away forclarity, taken along line 4--4 of FIG. 2;

FIG. 5 is a cross-sectional view, with the support frame broken away forclarity, taken along line 5--5 of FIG. 2;

FIG. 6 is a cross-sectional view, with the support frame broken away forclarity, taken along line 6--6 of FIG. 2;

FIG. 7 is a partial, schematic, perspective view of a chip mill havingan infeed chute with wings for dual cranes in accordance with theinvention;

FIG. 8 is an elevational view of an infeed chute with wings for dualcranes in accordance with the invention;

FIG. 9 is a top plan view of the infeed chute with wings for dual cranesin accordance with the invention;

FIG. 10 is a cross-sectional view taken along line 10--10 of FIG. 9;

FIG. 11 is a cross-sectional view taken along line 11--11 of FIG. 9;

FIG. 12 is a cross-sectional view taken along line 12--12 of FIG. 9; and

FIG. 13 is a cross-sectional view taken along line 13--13 of FIG. 9.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EXEMPLARY EMBODIMENT

An infeed chute 112 is provided in accordance with the present inventionwhich can receive logs transported thereto from two log cranessimultaneously or nearly simultaneously (FIG. 7) whereby the fullcapacity of the associated debarking drum 116 can be used to therebyincrease the efficiency of the debarking and chipping apparatus as awhole. The ability to receive simultaneous or near simultaneous loadsnot only allows the full capacity of the debarking drum 116 to be usedto maximize the efficient use of power and time but also reducesproduction delay which would otherwise result from interrupted feed as afurther load is retrieved by a single crane.

Thus, immediately as one crane 110 deposits its load in the chute 112,it can be moved to retrieve another load from its storage pile 114. Asthat crane is moving from the locus of the chute 112, the second crane111 can be depositing its load in the chute 112 of the invention. Asthose near simultaneous loads are being guided into the debarking drum116 and received in the debarking drum, the first crane 110 which hasretrieved another load and is returned to the chute 112. At that timeits load can be received in the chute 112 even in the event that theoriginal two near simultaneous loads are being fed into the debarkingdrum 116. Likewise, the second crane 111 soon returns to the locus ofthe chute 112 from its storage pile 115 and can deposit its next load.Thus, the infeed chute of the invention can receive crane loadssimultaneously or near simultaneously and can subsequently receivefurther loads without significant ejection of logs or log pieces andwithout binding thereby maximizing the efficiency of the system as awhole.

In order to receive and accommodate such significant and repeatedloading, the infeed chute 112 includes wings shown generally at 118which ensure that the loads can be received from the two cranes 110, 111without the cranes 110, 111 interfering with one another and yet ensuresthat the deposited logs are smoothly guided downwardly into thedebarking drum 116.

The novel structure of the invention can thus be appreciated by acomparison of the inventive infeed chute 112 with the conventional chute12 of FIGS. 1-6. To accommodate plural loads, the infeed chute 112 ofthe invention, as compared to the prior art infeed chute 12 of FIGS. 1-6is not simply increased by 100% at the inlet and maintained the same atthe outlet. On the contrary, in accordance with the invention thecentral infeed flow plate 120 is decreased in width as compared to theprior art central flow plate 20. Indeed, the central infeed plate 120 ofthe invention has a width of about one-half of the debarking drum inletas opposed to a width of about two-thirds of the debarking drum inlet aswas the case with the conventional chute 12. The trough plates 122 onthe other hand, in accordance with the invention, have a width at theuppermost, inlet end of the chute 112 significantly greater than thetrough plates 22 of the single crane chute 12. In the illustratedembodiment, the trough plates have a width of about 1.2 times greaterthan the width of the debarking drum inlet.

Providing a narrower central flow plate 120 and significantly widertrough plates 122, it has been discovered, provides a smoothly slopingtrough which guides the logs deposited thereon towards the inlet of thedebarking drum 116 without abrupt transitions and the attendant risk ofbinding.

Contrasting FIG. 10 with FIG. 3, furthermore, it can be seen that thecombination of central plate 120 and trough plates 122 defines a moresmoothly sloping structure for receipt of the logs. Thus the angle Cdescribed by the trough plates 122 and the central plate 120 is greaterthan 165 degrees and most preferably between about 170° and 175°.

Contrasting FIG. 11 with FIG. 4, it can be seen that the assembly of theinvention continues to define a smoothly sloped central plate and troughplate assembly, with angle C most preferably in the range of 170°-175°.The wing plates 124 of the inventive assembly, furthermore, have alesser slope than their counterparts in the prior structure. Indeed, inaccordance with the invention an angle D of about 125° to about 140° hasbeen found advantageous. The lesser slope again encourages a smoothtransition for the logs as they are fed downwardly towards the inlet ofthe debarking drum 116.

Contrasting FIG. 5 with FIG. 12, it can be seen, furthermore, that asthe inlet of the debarking drum is approached, the side walls 24 of theconventional assembly extend nearly vertically, whereas in accordancewith the invention wing walls 124, trough walls 122 and central plate120 define a more open trough which has a lesser slope, allowing alarger number of logs to be received while encouraging movement of suchlogs into the debarking drum 116.

With reference to FIG. 13, and the top plan view of FIG. 9, inaccordance with the present invention three substantially triangularinfeed transition plates 126 128, and 130 are defined immediatelyadjacent the debarking drum inlet. This channels the logs from thetrough, wing and central plates into the debarking drum 116. In theillustrated embodiment, the outermost transition plate 130 is in theform of a right triangle whereas the other two transition plates 126,128 are obtuse triangles. In the prior art assembly on the other hand,it should be recalled, only two transition plates 26,28 were provided,one in form of an obtuse triangle 26 and the other being a quadrilateralplate 28.

As shown in FIGS. 8, 10, and 12, an outer frame assembly 150 is providedfor the infeed chute 112 of the invention to support the wing walls orplates 124, to ensure the structural integrity of the structure. Thus,while the main frame assembly 152 does not differ significantly fromthat of the prior art infeed chute 12, additional wing supportassemblies 150 are provided on each lateral side of the trough assemblyat spaced locations along its length. In the illustrated embodiment, thewing support assemblies 150 are mounted at each longitudinal end of thechute and at a point two thirds of the way along the length.

Although dimensions of the infeed chute of the invention may be variedto accommodate the needs of a particular chip mill and crane arrangementand the particular size of the debarking drum without departing from theinvention, by way of example, the illustrated infeed chute has a totallength of about 33 feet and a width of about 34 feet. Furthermore, thechute has a height of about 351/2 feet to accommodate a drum which has acenterline about 19 feet above ground. For infeeding that drum, theoutlet of the plates of the chute is about 141/2 feet above ground. Atthe inlet end of the chute, the central plate 120 is about two feetbelow the top edge of the chute. Finally, in the illustrated embodiment,the debarking drum has an inner diameter of about ten feet.

Thus, the debarking infeed chute 112 provided in accordance with thepresent invention is capable of accommodating infeed from two log cranes110,111 simultaneously or nearly simultaneously by providing a centralfeed plate 120 of relatively smaller width and trough plates 122 ofgreater width and at a lesser slope than in the prior art assemblythereby to provide a smoothly and slightly inclined trough. Furthermore,wing plates 124 are provided which not only define containing side wallsbut continue and extend the trough width and as such are of less severevertical inclination than the prior art walls, again to receive aplurality of log loads and yet smoothly guide the same towards a commoninlet. Desirably, to accommodate the gentle slope and increased width ofthe chute assembly, three transition plates are provided adjacent thedebarker inlet to round out the flow thereinto.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is understood that the invention is not limited to the disclosedembodiment, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. An infeed chute having an inlet end; an outletend disposed adjacent a debarking drum of predetermined width; and aplurality of plate elements defining a vertically decending path fromsaid inlet end to said outlet end, said plurality of plate elementsincluding a central plate element having first and second lateral sideedges, first and second substantially triangular trough plate elements,each said trough plate element having an inner side edge and an outerside edge, each said trough plate element being disposed with its innerside edge extending along a respective lateral side edge of said centralplate element, and first and second substantially triangular wing plateelements, each said wing plate element being disposed along a respectiveouter side edge of a respective said trough plate element, each saidtrough plate element defining an angle C of greater than about 165degrees with said central plate element, each said wing plate elementdefining an angle D of greater than about 125 degrees with a respectivesaid trough plate element, whereby logs to be debarked can be receivedat least nearly simultaneously from two log cranes and guided into thedebarking drum.
 2. An infeed chute as in claim 1, wherein said troughplate elements have a first width adjacent said inlet end and a secondwidth adjacent said outlet end, said first width being greater than saidsecond width; and said wing plate elements have a first width adjacentsaid outlet end and a second width adjacent said inlet end, said firstwidth being greater than said second width.
 3. An infeed chute as inclaim 1, wherein said central plate element has a width of aboutone-half that of the debarking drum.
 4. An infeed chute as in claim 1,wherein adjacent said inlet end of the infeed chute, each of said troughplate elements has a width of about 1.2 times greater than that of thedebarking drum inlet.
 5. An infeed chute as in claim 1, furthercomprising a plurality of transition plates each coupled to at least oneof said central, trough, and wing plate elements thereby to define atransition from an open, U-shaped trough to a part circular infeed forthe debarking drum.
 6. An infeed chute as in claim 5, wherein there arethree transition plates provided on each longitudinal half of the chute.7. An infeed chute as in claim 6, wherein two of said three transitionplates of each side have an obtuse triangular shape and the thirdtransition plate has a substantially right triangular shape.
 8. Aninfeed chute as in claim 1, further comprising a sub-frame assembly forsupporting said central plate element and said trough plate elements anda wing sub-frame assembly for supporting said wing plate elements, saidwing sub-frame assembly being provided at spaced locations along thelength of the wing plate elements.
 9. An infeed chute as in claim 1,wherein said angle C is between about 170 and about 175 degrees.
 10. Aninfeed chute as in claim 1, wherein said angle D is between about 125and about 140 degrees.